1,055 research outputs found

    Techniques on vertical ridge augmentation: Indications and effectiveness.

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    Vertical ridge augmentation techniques have been advocated to enable restoring function and esthetics by means of implant-supported rehabilitation. There are three major modalities. The first is guided bone regeneration, based on the principle of compartmentalization by means of using a barrier membrane, which has been demonstrated to be technically demanding with regard to soft tissue management. This requisite is also applicable in the case of the second modality of bone block grafts. Nonetheless, space creation and maintenance are provided by the solid nature of the graft. The third modality of distraction osteogenesis is also a valid and faster approach. Nonetheless, owing to this technique's inherent shortcomings, this method is currently deprecated. The purpose of this review is to shed light on the state-of-the-art of the different modalities described for vertical ridge augmentation, including the indications, the step-by-step approach, and the effectiveness

    Optically powered radio-over-fiber systems in support of 5G cellular networks and IoT

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    We propose using power-over-fiber (PoF) in some part of future 5G cellular solutions based on radio access networks considering currently installed front-haul solutions with single mode fiber to optically power communication systems for 5G new radio (NR) data transmission. Simulations addressing design parameters are presented. Radio-over-fiber (RoF) transmission over single mode fiber (SMF) is experimentally implemented and tested for link lengths ranging from 100 m up to 10 km with injected PoF signals up to 2 W. 64QAM, 16QAM and QPSK data traffic of 100 MHz bandwidth are transmitted simultaneously with the PoF signal showing an EVM compliant with 5G NR standard, and up to 0.5 W for 256QAM. EVM of 4.3% is achieved with RF signal of 20 GHz and QPSK modulation format in coexistence with delivering 870 mW of optical power to a photovoltaic cell (PV) after 10 km-long SMF link. Using PoF technology to optically powering remote units and Internet-of-Things (IoT) solutions based on RoF links is also discussed.This work was supported in part by the Spanish Ministerio de Ciencia, Innovación y Universidades, Comunidad de Madrid and H2020 European Union programme under Grants RTI2018-094669-B-C32, Y2018/EMT-4892, and 5G PPP Bluespace project grant n°.762055, respectively

    Photochromic mechanism in oxygen-containing yttrium hydride thin films: An optical perspective

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    Oxygen-containing yttrium hydride thin films exhibit photochromic behavior: Transparent thin films reversibly switch from a transparent state to a photodarkened state after being illuminated with UV or blue light. From optical spectrophotometry and ellipsometry measurements of the transparent state and photodarkened state, it is concluded that the photochromic effect can be explained by the gradual growth, under illumination, of metallic domains within the initial wide-band-gap semiconducting lattice. This conclusion is supported by Raman measurements

    Early Science with the Large Millimeter Telescope: COOL BUDHIES I - a pilot study of molecular and atomic gas at z~0.2

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    An understanding of the mass build-up in galaxies over time necessitates tracing the evolution of cold gas (molecular and atomic) in galaxies. To that end, we have conducted a pilot study called CO Observations with the LMT of the Blind Ultra-Deep H I Environment Survey (COOL BUDHIES). We have observed 23 galaxies in and around the two clusters Abell 2192 (z = 0.188) and Abell 963 (z = 0.206), where 12 are cluster members and 11 are slightly in the foreground or background, using about 28 total hours on the Redshift Search Receiver (RSR) on the Large Millimeter Telescope (LMT) to measure the 12^{12}CO J = 1 --> 0 emission line and obtain molecular gas masses. These new observations provide a unique opportunity to probe both the molecular and atomic components of galaxies as a function of environment beyond the local Universe. For our sample of 23 galaxies, nine have reliable detections (S/N\geq3.6) of the 12^{12}CO line, and another six have marginal detections (2.0 < S/N < 3.6). For the remaining eight targets we can place upper limits on molecular gas masses roughly between 10910^9 and 1010M10^{10} M_\odot. Comparing our results to other studies of molecular gas, we find that our sample is significantly more abundant in molecular gas overall, when compared to the stellar and the atomic gas component, and our median molecular gas fraction lies about 1σ1\sigma above the upper limits of proposed redshift evolution in earlier studies. We discuss possible reasons for this discrepancy, with the most likely conclusion being target selection and Eddington bias.Comment: MNRAS, submitte

    A chimeric protein-based vaccine elicits a strong IgG antibody response and confers partial protection against Shiga toxin-producing Escherichia coli in mice

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    BackgroundShiga toxin-producing Escherichia coli (STEC) is a foodborne pathogen that causes gastrointestinal infections, ranging from acute diarrhea and dysentery to life-threatening diseases such as Hemolytic Uremic Syndrome. Currently, a vaccine to prevent STEC infection is an unmet medical need.ResultsWe developed a chimeric protein-based vaccine targeting seven virulence factors of STEC, including the Stx2B subunit, Tir, Intimin, EspA, Cah, OmpT, and AggA proteins. Immunization of mice with this vaccine candidate elicited significant humoral and cellular immune responses against STEC. High levels of specific IgG antibodies were found in the serum and feces of immunized mice. However, specific IgA antibodies were not detected in either serum or feces. Furthermore, a significantly higher percentage of antigen-specific CD4+ T cells producing IFN-γ, IL-4, and IL-17 was observed in the spleens of immunized mice. Notably, the immunized mice showed decreased shedding of STEC O157:H7 and STEC O91:H21 strains and were protected against weight loss during experimental infection. Additionally, infection with the STEC O91:H21 strain resulted in kidney damage in control unimmunized mice; however, the extent of damage was slightly lower in immunized mice. Our findings suggest that IgG antibodies induced by this vaccine candidate may have a role in inhibiting bacterial adhesion and complement-mediated killing.ConclusionThis study provides evidence that IgG responses are involved in the host defense against STEC. However, our results do not rule out that other classes of antibodies also participate in the protection against this pathogen. Additional work is needed to improve the protection conferred by our vaccine candidate and to elucidate the relevant immune responses that lead to complete protection against this pathogen

    Characterization of Adherent-Invasive Escherichia coli (AIEC) Outer Membrane Proteins Provides Potential Molecular Markers to Screen Putative AIEC Strains

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    Adherent-invasive E. coli (AIEC) is a pathotype associated with the etiopathogenesis of Crohn's disease (CD), albeit with an as-yet unclear role. The main pathogenic mechanisms described for AIEC are adherence to epithelial cells, invasion of epithelial cells, and survival and replication within macrophages. A few virulence factors have been described as participating directly in these phenotypes, most of which have been evaluated only in AIEC reference strains. To date, no molecular markers have been identified that can differentiate AIEC from other E. coli pathotypes, so these strains are currently identified based on the phenotypic characterization of their pathogenic mechanisms. The identification of putative AIEC molecular markers could be beneficial not only from the diagnostic point of view but could also help in better understanding the determinants of AIEC pathogenicity. The objective of this study was to identify molecular markers that contribute to the screening of AIEC strains. For this, we characterized outer membrane protein (OMP) profiles in a group of AIEC strains and compared them with the commensal E. coli HS strain. Notably, we found a set of OMPs that were present in the AIEC strains but absent in the HS strain. Moreover, we developed a PCR assay and performed phylogenomic analyses to determine the frequency and distribution of the genes coding for these OMPs in a larger collection of AIEC and other E. coli strains. As result, it was found that three genes (chuA, eefC, and fitA) are widely distributed and significantly correlated with AIEC strains, whereas they are infrequent in commensal and diarrheagenic E. coli strains (DEC). Additional studies are needed to validate these markers in diverse strain collections from different geographical regions, as well as investigate their possible role in AIEC pathogenicity

    Accurate evolutions of unequal-mass neutron-star binaries: properties of the torus and short GRB engines

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    We present new results from accurate and fully general-relativistic simulations of the coalescence of unmagnetized binary neutron stars with various mass ratios. The evolution of the stars is followed through the inspiral phase, the merger and prompt collapse to a black hole, up until the appearance of a thick accretion disk, which is studied as it enters and remains in a regime of quasi-steady accretion. Although a simple ideal-fluid equation of state with \Gamma=2 is used, this work presents a systematic study within a fully general relativistic framework of the properties of the resulting black-hole--torus system produced by the merger of unequal-mass binaries. More specifically, we show that: (1) The mass of the torus increases considerably with the mass asymmetry and equal-mass binaries do not produce significant tori if they have a total baryonic mass M_tot >~ 3.7 M_sun; (2) Tori with masses M_tor ~ 0.2 M_sun are measured for binaries with M_tot ~ 3.4 M_sun and mass ratios q ~ 0.75-0.85; (3) The mass of the torus can be estimated by the simple expression M_tor(q, M_tot) = [c_1 (1-q) + c_2](M_max-M_tot), involving the maximum mass for the binaries and coefficients constrained from the simulations, and suggesting that the tori can have masses as large as M_tor ~ 0.35 M_sun for M_tot ~ 2.8 M_sun and q ~ 0.75-0.85; (4) Using a novel technique to analyze the evolution of the tori we find no evidence for the onset of non-axisymmetric instabilities and that very little, if any, of their mass is unbound; (5) Finally, for all the binaries considered we compute the complete gravitational waveforms and the recoils imparted to the black holes, discussing the prospects of detection of these sources for a number of present and future detectors.Comment: 35 pages; small changes to match the published versio

    Recovering and harmonizing research cruises information

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    The IEO has maintained since late 60s, a local database with basic information on oceanographic campaigns, formerly known as ROSCOF reports, which were established in the framework of IODE initiatives, as a low-level inventory for future access to data. Technological advances in recent decades and different coordination activities between NODCs have favored the implementation of these reports in standardized digital formats (Cruise Summary Reports, CSR) that allow their integration in international repositories as SeaDataNet or POGO. However, this inventory and cataloging activity has suffered ups and downs over 40 years of activity, changes in storage criteria and periods of less activity. In the search for a unique criterion that can last over time and that unifies this information as much as possible with the data generated in these campaigns, an exhaustive review of the existing information has been carried out. The result has been the retrieval of information from short-term campaigns carried out on smaller vessels with great coastal activity, as well as updating information regarding old campaigns performed on the first half of the 20th century onboard of decommissioned vessels. All this is completed with the systematic campaigns carried out by INTECMAR in the Galician rias, research vessels operated by the national Fisheries Administration, and information on research surveys carried out by foreign ships in national waters, forming a catalog of more than 4000 entries. This approach is also followed by the UTM-CSIC, on its own-managed vessels and campaigns carried out since 1991. The common approach allows a unified response to the governmental needs for the planning of future campaigns, and in successive improvements in data recovering, archiving and accessing at NODC/CEDO

    Landscapes and bacterial signatures of mucosa-associated intestinal microbiota in Chilean and Spanish patients with inflammatory bowel disease

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    Inflammatory bowel diseases (IBDs), which include ulcerative colitis (UC) and Crohn’s disease (CD), cause chronic inflammation of the gut, affecting millions of people worldwide. IBDs have been frequently associated with an alteration of the gut microbiota, termed dysbiosis, which is generally characterized by an increase in abundance of Proteobacteria such as Escherichia coli, and a decrease in abundance of Firmicutes such as Faecalibacterium prausnitzii (an indicator of a healthy colonic microbiota). The mechanisms behind the development of IBDs and dysbiosis are incompletely understood. Using samples from colonic biopsies, we studied the mucosa-associated intestinal microbiota in Chilean and Spanish patients with IBD. In agreement with previous studies, microbiome comparison between IBD patients and non-IBD controls indicated that dysbiosis in these patients is characterized by an increase of pro-inflammatory bacteria (mostly Proteobacteria) and a decrease of commensal beneficial bacteria (mostly Firmicutes). Notably, bacteria typically residing on the mucosa of healthy individuals were mostly obligate anaerobes, whereas in the inflamed mucosa an increase of facultative anaerobe and aerobic bacteria was observed. We also identify potential co-occurring and mutually exclusive interactions between bacteria associated with the healthy and inflamed mucosa, which appear to be determined by the oxygen availability and the type of respiration. Finally, we identified a panel of bacterial biomarkers that allow the discrimination between eubiosis from dysbiosis with a high diagnostic performance (96% accurately), which could be used for the development of non-invasive diagnostic methods. Thus, this study is a step forward towards understanding the landscapes and alterations of mucosa-associated intestinal microbiota in patients with IBDs.This study was supported by Fondo Nacional De Desarrollo Científico y Tecnológico FONDECYT grant 1161161 to R. Vidal, CONICYT-PCHA/2014-21140975 fellowship to N. Chamorro, FONDECYT 1120577 and 1170648 to Hermoso MA and the Spanish Ministry of Economy projects CLG2015 66686-C3-1-P to Rosselló-Mora R., as well as funds from the European Regional Development Fund (FEDER) and NSF Dimensions in Biodiversity grant OCE-1342694. Support was also provided by a Millennium Science Initiative grant from the Ministry of Economy, Development and Tourism to Paredes-Sabja D

    Cumulative acquisition of pathogenicity islands has shaped virulence potential and contributed to the emergence of LEE-negative Shiga toxinproducing Escherichia coli strains

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    Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens causing severe gastroenteritis, which may lead to hemolytic uremic syndrome. The Locus of Enterocyte Effacement (LEE), a Pathogenicity Island (PAI), is a major determinant of intestinal epithelium attachment of a group of STEC strains; however, the virulence repertoire of STEC strains lacking LEE, has not been fully characterized. The incidence of LEE-negative STEC strains has increased in several countries, highlighting the relevance of their study. In order to gain insights into the basis for the emergence of LEE-negative STEC strains, we performed a large-scale genomic analysis of 367 strains isolated worldwide from humans, animals, food and the environment. We identified uncharacterized genomic islands, including two PAIs and one Integrative Conjugative Element. Additionally, the Locus of Adhesion and Autoaggregation (LAA) was the most prevalent PAI among LEE-negative strains and we found that it contributes to colonization of the mice intestine. Our comprehensive and rigorous comparative genomic and phylogenetic analyses suggest that the accumulative acquisition of PAIs has played an important, but currently unappreciated role, in the evolution of virulence in these strains. This study provides new knowledge on the pathogenicity of LEE-negative STEC strains and identifies molecular markers for their epidemiological surveillance.This study was supported by FONDECYT grant 1161161 to R. Vidal and CONICYT-PCHA/2014-63140238 fellowship to D. Montero. Work at USC-LREC was supported by Project PI16/01477 from Plan Estatal de I+D+I 2013-2016, Instituto de Salud Carlos III, Subdirección General de Evaluación y Fomento de la Investigación and FEDER, Ministerio de Economia, Industria y Competitividad, Gobierno de España and Project ED431C 2017/57 from the Consellería de Cultura, Educación e Ordenación Universitaria, Xunta de Galicia and FEDER. Fondecyt 11150966 to Felipe Del Canto. Consejo Nacional de Ciencia y Tecnología; [Fondo Nacional de Desarrollo Científico y Tecnológico].S
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